Medicine
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OBSERVATIONAL STUDY
Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction A Comparison Between 2 Brands of Stents Bing-Wei Ye, MD, Kuei-Chuan Lee, MD, PhD, Yun-Cheng Hsieh, MD, Chung-Pin Li, MD, PhD, Yee Chao, MD, PhD, Ming-Chih Hou, MD, and Han-Chieh Lin, MD
Abstract: Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P ¼ 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P ¼ 0.01). Cancer with gastric origin (HR: 0.25, P ¼ 0.045) and poststent chemotherapy (HR: 0.38, P ¼ 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P ¼ 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group. (Medicine 94(29):e1208) Abbreviations: CT = chemotherapy, ECOG = Eastern Cooperative Oncology Group, GJ = gastrojejunostomy, GOOSS = gastric outlet obstruction scoring system, HR = hazard ratio, MGOO = malignant gastric outlet obstruction, RT = radiotherapy, SD = standard Editor: Eva Zapata. Received: April 28, 2015; revised: June 23, 2015; accepted: June 29, 2015. From the Division of Gastroenterology (B-WY, K-CL, Y-CH, C-PL, YC, M-CH, H-CL), Department of Medicine; Cancer Center (YC); Endoscopic Diagnosis and Therapeutic Center (M-CH), Taipei Veterans General Hospital; and Department of Medicine (B-WY, K-CL, Y-CH, C-PL, YC, M-CH, H-CL), National Yang-Ming University School of Medicine, Taipei, Taiwan. Correspondence: Kuei-Chuan Lee, Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, 201, Section 2, Shih-Pai Road, Taipei 112, Taiwan (e-mail:
[email protected]). This study is in part supported by grant V103B-002 from Taipei Veterans General Hospital, Taipei, Taiwan. The authors have no conflicts of interest to disclose. Copyright # 2015 Wolters Kluwer Health, Inc. All rights reserved. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0, where it is permissible to download, share and reproduce the work in any medium, provided it is properly cited. The work cannot be changed in any way or used commercially. ISSN: 0025-7974 DOI: 10.1097/MD.0000000000001208
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deviation, SEMS = self-expandable metallic stent, UGI = upper gastrointestinal.
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INTRODUCTION
alignant gastric outlet obstruction (MGOO) is a late complication of intraabdominal malignancy, especially in pancreatic cancer and gastric cancer. It is common and has been reported up to 20% in pancreatic cancer patients and 35% in distal gastric cancer patients.1– 4 It can cause significant morbidity including intractable nausea, vomiting, poor oral intake, and severe weight loss. These symptoms lead to dehydration, malnutrition, cachexia, and poor quality of life. These patients are also put at the risk of aspiration pneumonia. Of these patients, the prognosis is poor with median survival about only 3 to 4 months.5 Two treatment modalities to relieve obstructive symptoms that are commonly used are surgical gastrojejunostomy (GJ) and self-expandable metallic stent (SEMS) placement. The technical and clinical outcomes between GJ and SEMS seem to be comparable.6 The GJ is associated with significant mortality and morbidity rate, prolonged hospital stay, delayed symptoms relief, and increased cost.6 –8 Although GJ has better survival outcome in patients with Eastern Cooperative Oncology Group (ECOG) 0–19; however, most patients who suffer from MGOO are already at preterminal stages with only limited life expectancies and are unsuitable for surgery. Thus, SEMS placement seems to be a good option in this patient population. SEMS insertion is an effective and safe alternative palliative procedure for MGOO. Roy et al6 reported that the stent placement had lower median length of stay in hospital and costs in comparison with GJ. Jeurnink et al8 found earlier food intake in stent group than GJ group. Espinel et al7 found that the enteral stent had lower 30 days mortality than GJ with 16.6% than 29.4%. The trend of low complication rate was also found with 4% versus 17.6%. There are also several commercially available enteral SEMS with a variety of stent lengths and designs to be chosen from, such as enteral Wallstent, enteral WallFlex, Hanarostent, Niti-S pyloric/duodenal stent, Comvi Niti-S pyloric/duodenal stent, and Bonastent. In our hospital, SEMS placement for MGOO in inoperable patients was performed since April 2010. Two brands of uncovered metallic stent (WallFlex stent and Bonastent) are available in our hospital. The safety and effectiveness of WallFlex stents for MGOO were already known in the previous study,10 but the related data in clinical use of Bonastent still lacks. In addition, no head-to-head study comparing the 2 brands is reported so far. Thus, we aimed to assess the efficacy and safety of metallic stent placement and compared the clinical outcome of both brands of stents in our patients. www.md-journal.com |
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METHODS Patients Seventy-one consecutive patients with inoperable intraabdominal malignancy causing MGOO and treated with metallic stent insertion were recruited retrospectively from April 2010 to April 2014. All cases were followed up to death or until February 2015 and received metallic stent placement at Taipei Veterans General Hospital, Taipei, Taiwan. They had symptoms of obstruction such as nausea, vomiting, abdominal fullness, and poor appetite. MGOO was confirmed by upper gastrointestinal (UGI) endoscopy and computed tomography scans. This retrospective study was approved by the Institutional Review Board of Taipei Veterans General Hospital and was in accordance with the ethical standards of Declaration of Helsinki. The informed consent was waived because of retrospective study design.
Stent Placement Several days before stent placement, a computed tomography scan and UGI endoscopy were performed to evaluate the site, severity, and the length of stricture. All patients received nasogastric tube drainage and received nil per os to minimize the risk of aspiration and ensure adequate gastric emptying. The tip of the UGI endoscope with wide caliber working channels (GIF-2T240 or GIF-2TQ260M; Olympus, Tokyo, Japan) was inserted in the area before the obstructive site. Then, a guide wire (Hydra Jagwire; Boston Scientific Corporation, Marlborough, MA) through the working channel of the endoscope was passed through the stricture under fluoroscopic guidance. The length and location of the stricture were measured by injecting watersoluble radiographic contrast. The length of the stent was determined by adding 4 to 6 cm to the stricture length. Using fluoroscopy for guidance, the uncovered metallic stents either WallFlex single-use duodenal stents (Boston Scientific Corporation) or Bonastents pyloric/ duodenal (Standard SciTech Inc, Seoul, South Korea) were implanted. Both the ends of the stents were 2 to 3 cm beyond the stricture ends. Before the procedure, we had provided the details of the 2 brands of stents including the price, manufacturing companies, and countries of origin to each patient. Because the metallic stents were not covered by our National Health Insurance, the selection in brands of the self-paid metallic stents was determined by the patients themselves.
Evaluation of the Degrees of Gastric Outlet Obstruction Gastric outlet obstruction scoring system (GOOSS) was used to measure the degrees of outlet obstruction. On the basis of oral intake, a GOOSS value was assigned as a 4-point scale: 0 for no oral intake, 1 for liquid diet only, 2 for soft diet, and 3 for low residual diet or regular diet.11
Definition of Clinical, Technical Success and Procedure-Related Complications The clinical success was defined as resolution of obstructive symptoms with improved oral intake at day 7 after the stent implantation. The technical success was defined as the adequate deployment of the stent with proper position across stricture. Procedure-related complications were separated into minor and major complications. The minor complications were referred to as no life-threatening complications including abdominal pain, nausea, and vomiting. The major complications mean lifethreatening complications, such as aspiration pneumonia, sepsis, bleeding, and perforation.12
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Data Collection The data from patients’ medical records including radiology reports, procedure reports, daily notes, and phone interview were obtained. The data we collected included the baseline characteristics, GOOSS values, complications, procedure time, duration of stent patency, and survival.
Statistics Analysis All the continuous variables are presented as mean standard deviation (SD) or number (percentage) (n, %). The GOOSS value changes were compared by Wilcoxon signed rank test. The baseline characteristics between 2 stents were compared by Student t test or x2/Fisher exact test depending on whether the variables were continuous or categorical. The subgroup analysis of duration of stent patency and survival among different cancer origins were analyzed by 1-way analysis of variance. The univariate analysis was performed by Kaplan–Meier analysis compared with the log-rank test. Variables with P values 0.99 (9.0) 26.8 (8.8) 0.99 (3.9) 20.1 (2.8) 0.97 (0.6) 2.7 (0.7) 0.30 (1.5) 2.4 (1.0) 0.78 (0.5) 1.2 (0.9) 0.26 (0.8) 2.4 (0.9) 0.59 (0.8) 2.6 (0.7) 0.23 0.32 (4.9%) (2.4%)
0 (0%) 0 (0%)
(9.8%) (9.8%) (14.6%) (34.1%) (31.7%) (0%) (2.4%) (24.4%)
3 3 3 8 4 4 0 4
0.95 (10%) (10%) (10%) (26.7%) 0.61 (13.3%) 0.10 (13.3%) 0.03 (0%) >0.99 (13.3%) 0.37
Data were expressed as mean (SD) or number (%). -1 ¼ 1 month later, BMI ¼ body mass index, ECOG ¼ Eastern Cooperative Oncology Group, GOOSS-D7/D30 ¼ gastric outlet obstruction scoring system values at day 7/day 30, SD ¼ standard deviation. P < 0.05. # These parameters were collected from 66 patients (WallFlex/Bonastent: 37/29) because of early death (within 30 d after stent insertion) in some patients (WallFlex/Bonastent: 4/1).
aspiration pneumonia after stent insertion. One of the 2 patients recovered after adequate antibiotic treatment and was discharged 1 week later. However, the other patient developed respiratory failure and died 3 days later because of no further resuscitation requested by the patient. One patient (1.4%) became septic after stent placement and recovered after antibiotic treatment. One (1.4%) patient receiving chemotherapy (CT) after stent insertion had stent migration at day 38. The endoscope finding showed that stent was dislodged at the third portion of duodenum and the stent was retrieved without adverse events. However, stent fracture developed in 4 patients during the follow-up period. Two of 4 patients were found because of the development of GOO symptoms that were relieved by another stent insertion. The fractured parts were found to be dislodged at fundus and were retrieved out without adverse events before another stent insertion. However, the others were found incidentally without obstructive symptoms at routine follow-ups of computed tomography scans for evaluation of the CT responses. The fractured stent from one of them disappeared while performing UGI scope for retrieval and passed out with stool spontaneously. Another fractured stent was still in position and fixed by ingrowth of tumor. The time from insertion to stent fracture was 90, 146, 151, and 153 days, respectively. Three of 4 had received poststent placement CT and only 1 of them showed disease progression. www.md-journal.com |
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Twenty patients had recurrence of symptoms of GOO. One of these patients suffered from stent migration after CT as mentioned earlier and received radiotherapy (RT) only after the old stent was removed. Two of them suffered from stent fracture and received another stent insertion smoothly. The other 17 patients developed stent restenosis. Six of the 17 patients (35.3%) with stent restenosis received supportive care only because of terminal stage and the requests of no further invasive intervention. Eight of the 17 patients (47.1%) with stent restenosis received stent-in-stent insertion (see figure, Supplemental Digital Content 3, http://links.lww.com/MD/A338, which illustrates the outcomes of patients with MGOO treated with metallic stent placement).
Factors Predicting Restenosis The mean duration of the stent patency was 132.7 days (ranged from 13 to 570 days). Figure 2A shows the time to restenosis after stent placement. In univariate and multivariate analyses, only GOOSS 3 point at day 7 was significantly associated with stent patency (Table 3 and Figure 2B).
Factors Predicting Survival In total, 69 patients died during the follow-up period. Five patients passed away within 30 days after stent insertion (WallFlex/Bonastent: 4/1, P ¼ 0.39). One patient death in WallFlex group was because of procedure-related aspiration pneumonia. Four patients deceased because of natural terminal course (WallFlex/Bonastent: 3/1). In the univariate analysis, several factors including female sex, advanced ECOG state, nongastric cancer origin, obstruction level in duodenum, previous RT, no poststent CT, peritoneal carcinomatosis, the presence of ascites, and GOOSS
